It is known to cast concrete bodies with pickup bolts having stems embedded in the body and heads exposed in part-spherical recesses. Such an arrangement is shown in my earlier U.S. Pat. Nos. 4,173,367 and 3,499,676. A concrete body thus equipped can be relatively easily and safely handled by an appropriate puckup unit. As the head of the pickup bolt is recessed in the concrete body, it in no way interferes with normal handling of the body, and the recess can even be filled once the body is emplaced, if necessary.
Forming the recess around the head of the pickup bolt is a relatively tricky job entailing the use of a special apparatus. The apparatus has a semispherical outer surface formed with a slot that terminates at its center. After sliding a bolt along the slot to the blind end thereof, so that the head of the bolt lies within the apparatus, the slot is closed by an elastic or slidable member. Concrete is then poured around the bolt and apparatus. Once the concrete is hardened the apparatus is slid off the bolt with the stem of the pickup bolt either pushing aside the elastic lips of the slot or the slidable cover of the slot being moved out of the way.
Such devices frequently leak somewhat at the slot. Thus concrete finds its way into the apparatus and makes it extremely difficult, if not impossible, to remove it. Even modest leakage that does not greatly impede removal of the apparatus frequently leaves a concrete lump in the recess which must be removed before a pickup unit can be fitted in the recess over the bolt head.